Enhanced oil recovery includes processes for increasing the amount of hydrocarbon material (e.g., crude oil, natural gas, etc.) recovered from a subterranean formation. Methods of enhanced oil recovery include water flooding, steam assisted gravity drainage (SAGD), steam flooding (e.g., cyclic steam stimulation (CSS)), and related methods. In these processes, a carrier fluid (e.g., water, brine, steam, etc.) is injected into a subterranean formation through injection wells to heat and/or sweep a hydrocarbon material contained within interstitial spaces (e.g., pores, cracks, fractures, channels, etc.) of the subterranean formation toward production wells offset from the injection wells.
However, heavy hydrocarbon materials such as hydrocarbons having an API gravity of about 22 (specific gravity of about 0.92) or lower, or bitumen (e.g., bituminous sands including oil sands and tar sands) often exhibit a high viscosity and, therefore, are often difficult to produce. The high viscosity of such heavy hydrocarbons makes them difficult to transport from a subterranean formation.
One method of lowering the viscosity of hydrocarbons in subterranean formations is to flood the formation with steam. Steam increases the temperature of the hydrocarbons in the formation, which lowers the viscosity of the hydrocarbons and allows the hydrocarbons to drain or be swept toward an oil well to be produced. Steam can also condense into water, which can then act as a low viscosity carrier phase for an emulsion of the hydrocarbon and the water, allowing heavy hydrocarbons to be more easily produced. One or more additives may be added to the carrier fluid to assist in the extraction and subsequent processing of the hydrocarbon material. However, many of the additives conventionally used to assist in the extraction and subsequent processing of hydrocarbon materials may not reduce the viscosity of the heavy hydrocarbons enough to effectively transport and recover the heavy hydrocarbons.